Putative Echinoderm Fossil Cotyledion from Chengjiang Biota

Cotyledion tylodes

Phylum Echinodermata (?)

Geological Time: Early Cambrian (~525 million years ago)

Size (25.4mm=1 inch): 12 mm long, 6 mm across on a 43 mm by 38 mm matrix

Fossil Site: Chengjiang Maotianshan Shales, Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Mafang, Anning, Kunming, Yunnan Province, China

Cotyledion tylodes chengjiangDescription: This is an example of the incredible diversity of early life known from the Chengjiang Biota. The diversity of soft-tissue fossils is astonishing: algae, medusiforms, sponges, priapulids, annelid-like worms, echinoderms, arthropods (including trilobites), hemichordates, chordates, and the first agnathan fish make up just a small fraction of the total. Numerous problematic forms are known as well, some of which may have represented failed attempts at diversity that did not persist to the present day. While some researchers place this one in the Problematica, others believe it is an early echinoderm much like the crinoids to come later. The calyx-like cap and stem are indeed evocative of such an assignment, perhaps more than some sort of convergent evolution. Whatever the correct assignment, this is a most unusual example.

Also see: Chengjiang Biota List Chengjiang Fossils

click fossil pictures to enlarge

l Fossil Mall Home l Fossils Science Section l

l Paleontology & Fossils l Paleobiology and Geologic Timeline l
l Fossil Amber l Ammonite Fossils l Dinosaur and Reptile Fossils l Fossil Kits l
l Crinoids and Echinoderms l Fish Fossils l Fossil Dealers l Insect Fossils l Invertebrate Fossils l
l Plant Fossils l Stromatolites l Trace & Ichnofossils l Trilobite Fossils l Vertebrate Fossils l